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Feb 21, 2024 394 likes •528 views

draft-anderson-forces-model-00 Todd A. Anderson Intel Labs Architecture CE Set CE Set CE CE CE CE CE Manager Gc Gr Gr Gr CE CE Gl Gp FE FE FE Manager Gf Gi Network Element Forwarding Element Model

SLIDE 1

draft-anderson-forces-model-00

Todd A. Anderson Intel Labs

SLIDE 2

Network Element CE Set

Architecture

Gp CE CE CE Gr … CE Manager FE Manager Gl Gf Gc Gi … FE CE Set CE CE CE Gr … Gr … FE

SLIDE 3

“Capability” Level “Stage” Level

Forwarding Element Model

Goal: define a way to express the

capabilities of a FE in a manner convenient to CEs.

Solution: use a two level hierarchy.

Logical Function Forwarder Meter Shaper Demux Classic IPv4 URL LB Switch Token Bucket Leaky Bucket L2Proto Demux IPProto Demux 5-tuple Demux

SLIDE 4

Stage Level

Gives an overview of what the FE can do in

terms of the stages it supports.

– Need a namespace for different stage types.

Allows multiples of the same stage in a FE.

– Need per stage instance IDs.

Allows the description of arbitrary stage

topologies.

Estimate 15-20 kinds of stages.

SLIDE 5

Capability Level

Describes the detailed abilities of each stage instance.
Uses a uniform methodology across different stages.
Each stage does at most 5 things:

– Classifies the packet. – Acts on the result of the classification. – Keeps statistics. – Generates events. – Uses parameters.

Stages can be:

– Read-only. – Have default classification/action pairs or parameters. – Have restrictions on allowable values.

SLIDE 6

Classification Abilities

Variable length sequence of “properties” on

which the stage can classify.

Two varieties of properties:

– Packet properties (e.g., IPproto, SIP, DIP, TOS) – Metadata properties (e.g., ingress/egress port)

Uses a property namespace.

SLIDE 7

Action Abilities

Variable length sequence of “actions” that

the stage can perform.

Three varieties of actions:

– Packet editing (e.g., modify TOS or DIP). – Metadata editing (e.g., set egress port). – Target selection (e.g., send packet to “drop” target).

Uses an action namespace.

SLIDE 8

Event Abilities

Variable length sequence of “events” that

the stage might generate.

Example events: packet redirection, port

up/down, forwarding table miss.

Uses an event namespace.

SLIDE 9

Statistics Abilities

Variable length sequence of “statistics” that

the stage maintains as it processing packets.

Example statistics: # of packets processed, #
f forwarding table misses.
Uses a statistics namespace.

SLIDE 10

Parameter Abilities

Variable length sequence of “parameters”

used by the stage.

Parameters are the “knobs and dials” of the

stage.

Affects how the stage processes

packets…not a per packet configuration.

Uses a parameter namespace.

SLIDE 11

Default Values

Stage capability description must include:

– # of default classification/action entries. – # of default properties.

– List of TLVs for each classification/action entry. – List of TLVs for each property.

T = one of the namespace “names”.
L = straight-forward.
V = a standard data structure associated

with the given name.

SLIDE 12

Restrictions on Allowable Values

Stages may place restrictions on the values
f properties, actions, parameters, statistics,
r events.
Solution:

– For each ability, the min and max allowable values are specified using the existing TLV approach. – For properties, equality, inequality, and range matching abilities are also specified.

SLIDE 13